Jon-ann Perhaps I am too loyal a student of my parasitology professor, but in my humble opinion, flea collars are a waste of money. Unless of course you're trying to kill only the fleas on your animals neck! ;) I'm not sure if flea collars are safe for ferrets or not -- myself, I don't think I'd risk it even if they supposedly were, but Dr. Williams can tell you for sure probably. The reason your fleas are returning is not because your ferret(s) don't have round-the-clock protection from a flea collar. Most likely it is because you have immature fleas in your carpeting and in the ferrets' bedding. Find out from your vet what is a safe environmental treatment, and zap the whole house, at least the carpeted parts. Be sure to pay special attention to underfurniture areas, especially underbeds -- the immature fleas are attracted to the cool, dark environmnent there. Treat your ferrets at the same time as you treat their environment, and whenever you take them outside go over them with a flea comb to be sure to get rid of any they may have picked up. It's a hassle, but your problem won't go away until you treat the environment around your pets, not just them. But then they should stay away, as long as you watch out for them. Good luck! Laura Laura L'Heureux U. of Illinois Vet Med Class of `96 [log in to unmask] [Posted in FML issue 0979]